The script was inspired by a fight that Stallone watched between Chuck Wepner and Muhammad Ali. Ali was predicted to knock Wepner out in the third round.

In the 9th round, Wepner sent Ali to the canvas. Mr. Ali quickly got up and went on to un-load on Wepner. Not until the 15th round with 19-seconds left in the fight did the ref call a TKO…